<!DOCTYPE html>
<html>
<head lang="en">
    <meta charset="UTF-8">
    <title></title>
    <style type="text/css">
        div{
            margin: 200px auto;
            width: 300px;
            height: 300px;
            text-align: center;
            line-height: 300px;
            font-size: 30px;
            border: solid 1px #aaa;
        }
    </style>
</head>
<body>

<div>登录成功</div>


</body>
</html>